1. Field Of The Invention
The present invention relates to a drive mechanism of a zoom lens barrel.
2. Related Art Statement
Zoom lens barrels disclosed in U.S. Pat. No. 5,661,609 and U.S. Pat. No. 5,739,962 each have such structure that one lens frame between two lens frames moved at the time of focusing is provided with an end surface cam and the end surface cam is contacted to another lens frame. Furthermore, when zooming, the one lens frame is rotated to change a distance between lens groups.
Nevertheless, in each of the above zoom lens barrels, a lens frame is rotated around an optical axis by zooming. Therefore, since cores of the lenses change according to a zooming position, this is not desirable for optical performance.